Gary,
Sorry to come in late after your request. The others have already given you good info. How did you get the idea that it is a ca 1934 gun? It is much earlier than that. If it had been a 1934 gun the month and year of proof would have been shown. The 12 in a circle indicates it was chambered for the "standard" length shells. This was 2 1/2-2 9/16" for 16 ga. and we often see this attributed to 12 ga.; but I believe the "standard" chamber for 12 ga. was actually 2 5/8", as Raimey mentioned. I see no indication that it has other than the "standard" chamber now. There is a lot of disagreement concerning the use of 2 3/4" shells, you have to make your own decision on that.
Mike
